You would expect people fleeing war zones to include a reasonable spread of men and women of various ages, plus children. However based on the pictures we see of the numerous small boats making the crossing, the people in these boats are predominantly younger men. Why do you think that is?
I've posted this before.
Let's suppose you are in a war zone. There is you, Mrs Stevo, Bill Stevo aged 12, Fred Stevo aged 19 and Doris Stevo aged 15. You also have Grandpa Stevo now 76 and Grandma Stevo aged 71.
You have enough gold and cash to pay for one member of your family to get to a safe haven after which they can hopefully start to get the rest of your family out via safer routes. They can earn money in the UK which is worth more than your currency which is either worthless due to the war or impossible to get hold of due to the banks being bombed and all.
Who do you send?
You know that Doris and Mrs Stevo stand a very high chance of being raped or trafficked into slavery. You don't send them. You could send yourself. You have skills, you are middle aged and could survive the journey and get a good job. The problem is that if you go, that leaves your wife, children and elderly parents in a war zone. That increases the likelihood of your wife and daughter being raped, your possessions stolen, family killed etc. Too risky.
The person most likely to survive the arduous journey to claim asylum is your oldest male son. He has some English and you know people who have made it to the UK who will help him if he can get there. He doesn't speak German, or French or Italian and you don't know anyone in those countries.
So the UK is the target. You give him the money / gold for the traffickers and pray that you will see him again. He is young, fit and has some basic skills to get a job.